US Patent No. 9,296,103

CONTROL DEVICE FOR ROBOT FOR CONVEYING WORKPIECE


Patent No. 9,296,103
Issue Date March 29, 2016
Title Control Device For Robot For Conveying Workpiece
Inventorship Takahiro Iwatake, Yamanashi (JP)
Assignee FANUC CORPORATION, Yamanashi (JP)

Claim of US Patent No. 9,296,103

1. A control device for a robot, the robot comprising a tool for holding a workpiece, and a force measuring part for measuring
a force acting on the tool from the workpiece when the workpiece is held by the tool, the robot being adapted to hold and
convey the workpiece placed in a three-dimensional space, the control device comprising:
a center-of-gravity position calculating part configured to calculate, based on force data measured by the force measuring
part for a plurality of postures of the robot holding the workpiece, a center-of-gravity position of the workpiece held by
the tool when the robot holds and conveys the workpiece;

a processing part configured to carry out, based on a positional relationship between a position of the tool and the center-of-gravity
position of the workpiece, at least one of

an estimation process for estimating a holding state of the workpiece held by the tool,
a determination process for determining a type of the workpiece held by the tool, and
a testing process for testing a quality of the workpiece held by the tool,
wherein the estimation process pertains to
stability of the holding state of the workpiece held by the tool, or
a position and posture of the workpiece held by the tool, or
a longitudinal direction of the workpiece held by the tool, or
a face of the workpiece on which the workpiece is held by the tool; and
an operating command modifying part
configured to modify, based on a result of (i) the estimation process pertaining to stability of the holding state of the
workpiece held by the tool, or (ii) the position and posture of the workpiece held by the tool, or (iii) the longitudinal
direction of the workpiece held by the tool, an operating command to the robot, and at least one of operations:

changing a moving speed of the robot at the time of conveying the workpiece held by the tool;
correcting a position and posture of the workpiece at the time of conveying the workpiece; and
correcting a position and posture of the workpiece and moving the workpiece to a destination,
or configured to modify an operating command to the robot, based on a result of the estimation process on the holding state
of the workpiece pertaining to a face of the workpiece on which the workpiece is held by the tool,

or configured to modify an operating command to the robot and change a destination of conveyance of the workpiece, based on
the type of the workpiece held by the tool or on a result of the testing process on the workpiece.